Effects of microstructure in ethylene glycol oxidation on graphite supported platinum electrodes

Activities of graphite supported and polycrystalline Pt in electrocatalytic oxidation of ethylene glycol in neutral unbuffered Na2SO4 solutions have b een compared. Morphology and microstructure of supported Pt electrodes have been studied using scanning electron microscopy, high-resolution transmiss ion electron microscopy and X-ray diffraction. Specific activity of Pt elec trodes and sensitivity to poisoning has been found to depend strongly on th eir microstructure. Supported electrodes appear to be from four to six time s less active than polycrystalline PI in the potential region between 0.3 a nd 0.9 V vs. SHE but much more stable to self-poisoning. The electrode micr ostructure has much less effect on the activity at high (over 0.9 V vs. SHE ) anodic potentials. (C) 1998 Elsevier Science Ltd. All rights reserved.